The invention relates to inertial sensors, and more particularly to inexpensive gyroscopes fabricated from molded components.
The design features of conventional inertial sensors, such as gyroscopes, for commercial and military applications utilize structural support elements machined from materials, such as aluminum, beryllium, and stainless steel. Generally, these support elements are manufactured using standard machining processes.
The gyro sub-component structures often depend in shape and size upon machining requirements. Typically, a component, such as a gimbal must initially be rough machined and then heat treated. Final machining operations may then be performed, including the machining of slots, holes, and grooves. The part is then stress-relieved. Expensive fixturing is then required for gyro assembly operations, such as alignment of the signal and torque generator rotors, motor stator and wheel. Subsequently, encapsulation operations are typically required. All these assembly operations are usually performed by hand and are quite time consuming and correspondingly expensive.
Instrument production analyses of commercial and military inertial sensors using conventional design features indicate that approximately 75% of the total unit production costs can be related directly to support element materials and fabrication and assembly operations.
Furthermore, instruments manufactured by the prior art methods are subject to substantial lot-to-lot and unit-to-unit variations, for example, due to machining tolerances or contamination resulting from part handling. In addition, many critical assembly operations are operator-sensitive, and are difficult to monitor. To overcome some of these effects, sensor fabrication operations are often performed in an expensive clean room facility.
Accordingly, it is an object of the invention to provide inertial sensors produced by precision, high volume production fabrication techniques.
It is another object of the invention to provide inertial sensors constructed of inexpensive materials.
It is still another object of the invention to create components for gyroscopes that require simplified design with very few piece parts.
It is a further object of the invention to provide inertial sensors characterized by minimal in-process assembly operations and tooling.